/*
 * Copyright (C) 2007 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.android.dx.dex.code.form;

import com.android.dx.dex.code.DalvInsn;
import com.android.dx.dex.code.InsnFormat;
import com.android.dx.util.AnnotatedOutput;

/**
 * Instruction format for nonstandard format instructions, which aren't
 * generally real instructions but do end up appearing in instruction lists.
 * Most of the overridden methods on this class end up throwing exceptions, as
 * code should know (implicitly or explicitly) to avoid using this class. The
 * one exception is {@link #isCompatible}, which always returns {@code true}.
 */
public final class SpecialFormat extends InsnFormat {

	/** {@code non-null;} unique instance of this class */
	public static final InsnFormat THE_ONE = new SpecialFormat();

	/**
	 * Constructs an instance. This class is not publicly instantiable. Use
	 * {@link #THE_ONE}.
	 */
	private SpecialFormat() {
		// This space intentionally left blank.
	}

	/** {@inheritDoc} */
	@Override
	public String insnArgString(DalvInsn insn) {
		throw new RuntimeException("unsupported");
	}

	/** {@inheritDoc} */
	@Override
	public String insnCommentString(DalvInsn insn, boolean noteIndices) {
		throw new RuntimeException("unsupported");
	}

	/** {@inheritDoc} */
	@Override
	public int codeSize() {
		throw new RuntimeException("unsupported");
	}

	/** {@inheritDoc} */
	@Override
	public boolean isCompatible(DalvInsn insn) {
		return true;
	}

	/** {@inheritDoc} */
	@Override
	public void writeTo(AnnotatedOutput out, DalvInsn insn) {
		throw new RuntimeException("unsupported");
	}
}
